1. Field of the Invention
The invention relates to a heat pipe, in particularly, to a loop heat pipe.
2. Description of Related Art
The working principle of a heat pipe is to transfer heat through the evaporation and condensation of a working fluid. First, a liquid working fluid absorbs the heat generated from the heat-generating element adjacent to an evaporator of the heat pipe and evaporates to a vapor. When the vapor working fluid encounters a slight pressure difference, the vapor working fluid flows to a condenser of the heat pipe, and is condensed into liquid at the condenser and discharges heat. The liquid working fluid condensed at the condenser is transferred back to the evaporator through a capillary structure on the inner surface of the heat pipe. Therefore, the heat pipe is adapted for dissipating heat from the heat-generating element. Currently, several patents relating to the heat pipe are recited, such as US Patent No. 20080078530 and Taiwan Patent No. 1248781 and No. 592033.
Taiwan Utility Model Patent No. M256674 discloses a loop heat dissipating device, in which a liquid working fluid in a compensation room between two capillary structures may absorb heat and evaporate, and thus the pressure difference at two ends of the compensation room disappears, resulting in a problem that the vapor working fluid may not flow.
Taiwan Utility Model No. M246563 discloses a loop heat pipe. The hoop heat pipe uses a dense capillary structure to absorb a liquid working fluid, so as to prevent the liquid working fluid from flowing to the condenser. However, the dense capillary structure may firmly absorb the liquid working fluid, so the liquid working fluid is hard to be supplied to the evaporator.